1. A Policy on Geometric Design of Rural Highways;American Association of State Highway Officials,1966
2. A Policy on Design of Urban Highways and Arterial Streets;American Association of State Highway Officials,1973
3. Optimal peak-load pricing, investment, and service levels on urban expressways;Keeler;J. Pol. Econ.,1977
4. Spacing and Location of Interchanges on Freeways in Urban and Suburban Areas;Leisch,1958